Try out a Scar-Vet, with Light armour, Sword of the Hornet, Enchanted Shield, and Potion of Speed.
the total cost of this guy comes out to exactly 200 points less than chakax, and he has a 2+ AS, Always Strike First all the time, when needed he can use the potion to get I7 ASF, which will quite regularly give him a rerol to hit, every Stat is the same as chakax and the only benefit chakax has over him would be that in challenges the enemies magic items are mundane, and 5+ ward save in challenges, that is it.
Alternatively give the same scarvet Armour of Fortune, Gold Sigil Sword, and a shield, same 2+ AS with a 5+ WS all the time, plus he is hitting first against almost everything, and this one is only three points more than the first one.
So, for the Price of Chakax, we could get BOTH of the two scar-vets I put forward and they are more survivable in and out of challenges (maybe as survivable in challenges).